An overview of the biological metal uptake pathways in Pseudomonas aeruginosa

Abstract

Biological metal ions, including Co, Cu, Fe, Mg, Mn, Mo, Ni and Zn ions, are necessary for the survival and the growth of all microorganisms. Their biological functions are linked to their particular chemical properties: they play a role in structuring macromolecules and/or act as co-factors catalyzing diverse biochemical reactions. These metal ions are also essential for microbial pathogens during infection: they are involved in bacterial metabolism and various virulence factor functions. Therefore, during infection, bacteria need to acquire biological metal ions from the host such that there is competition for these ions between the bacterium and the host. Evidence is increasingly emerging of "nutritional immunity" against pathogens in the hosts; this includes strategies making access to metals difficult for infecting bacteria. It is clear that biological metals play key roles during infection and in the battle between the pathogens and the host. Here, we summarize current knowledge about the strategies used by Pseudomonas aeruginosa to access the various biological metals it requires. P. aeruginosa is a medically significant Gram-negative bacterial opportunistic pathogen that can cause severe chronic lung infections in cystic fibrosis patients and that is responsible for nosocomial infections worldwide.

Cyclic Hydroxamic Acid Analogues of Bacterial Siderophores as Iron‐Complexing Agents prepared through the Castagnoli–Cushman Reaction of Unprotected Oximes

“…Cyclic hydroxamic acid (N-hydroxylactam) motifs are widely displayed in naturalp roducts as well as synthetic enzyme inhibitors. Their ability to chelate metal ions is the principald eterminant of their biological activity.E xamples shown in Figure 1i nclude microbial siderophores (procaryotic matabolites excreted into the extracellular spacet os cavenge, by chelation, iron neededf or growth and differentiation) [1] such as scabichelin(1), [2] oxachelin (2), [3] andt he simple N-hydroxy-3,4dihydroisoquinolin-1-one(3)i solated from Streptomyces griseus. [4] Chelation to the prosthetic zinc ion is the principal mode of action of HIV integrase inhibitors (such as 4), [5] matrix metalloprotease inhibitors (exemplified by 5 [6] and 6 [7] )a nd histone deacetylase inhibitors (such as 7).…”

“…The idea of O-acylation (i. e. the formation of 13)b eing in competition with the reactionp ath leading to 12 (involving no acylation step) is supported by the following evidence (Scheme 3). In one experiment, addition of imine 8a to as uspensiono f13 a in acetonitrile led, after stirring the reaction mixture at room temperature for fived ays, to the formation of tetrahydroisoquinolonic acid 15 (i. e. the CCR product of HPA and 8a)a sa5:1 trans/cis mixturea nd oxime 11 a (according to 1 HNMR spectroscopy analysiso ft he reactionm ixture, see the Supporting Information pS38). In the other experiment, Omethylo xime 16 was exposed to HPAi nr efluxing toluene, which gave respective CCR product 17.…”

Influence of the Hfq and Crc global regulators on the control of iron homeostasis in Pseudomonas putida

“…Simplified diagram of the synthesis, export and uptake of pyoverdine in Pseudomonas, and the involvement of the Fur protein and the PrrF1 and PrrF2 sRNAs in the regulation of iron homeostasis. The diagram is based on what it is known for different pseudomonads (see Cornelis et al, 2009;Cornelis, 2010;Schalk and Guillon, 2013;Llamas et al, 2014;Schalk and Cunrath, 2016). The colours indicate the expression trend in the Hfq-null strains (red, higher expression, green, lower expression).…”

Receptor uptake arrays for vitamin B12, siderophores, and glycans shape bacterial communities

“…When does it pay to express receptors at a constant level rather than adjust in response to perceived changes in availability? Previous studies of uptake provide a basis for these more advanced questions (Degnan, Barry, et al 2014;Schalk & Cunrath, 2016).…”